/**
 * @file Arduboy2.cpp
 * \brief
 * The Arduboy2Base and Arduboy2 classes and support objects and definitions.
 */

#include "Arduboy2.h"
#include "ab_logo.c"
#include "glcdfont.c"
#include "WMath.h"
#include "Game/GamePrivate.h"

#define power_timer0_disable()

//================================
//========== class Rect ==========
//================================

Rect::Rect(int16_t x, int16_t y, uint8_t width, uint8_t height)
    : x(x), y(y), width(width), height(height)
{
}

//=================================
//========== class Point ==========
//=================================

Point::Point(int16_t x, int16_t y)
    : x(x), y(y)
{
}

//========================================
//========== class Arduboy2Base ==========
//========================================

uint8_t* Arduboy2Base::sBuffer;

Arduboy2Base::Arduboy2Base()
{
    sBuffer = Game_DispGetBuffer();
    currentButtonState = 0;
    previousButtonState = 0;
    // frame management
    setFrameDuration(16);
    frameCount = 0;
    justRendered = false;
}

// functions called here should be public so users can create their
// own init functions if they need different behavior than `begin`
// provides by default
void Arduboy2Base::begin()
{
    boot(); // raw hardware

    display(); // blank the display (sBuffer is global, so cleared automatically)

    flashlight(); // light the RGB LED and screen if UP button is being held.

    // check for and handle buttons held during start up for system control
    systemButtons();

    audio.begin();

    bootLogo();
    // alternative logo functions. Work the same as bootLogo() but may reduce
    // memory size if the sketch uses the same bitmap drawing function
//  bootLogoCompressed();
//  bootLogoSpritesSelfMasked();
//  bootLogoSpritesOverwrite();
//  bootLogoSpritesBSelfMasked();
//  bootLogoSpritesBOverwrite();

    waitNoButtons(); // wait for all buttons to be released
}

void Arduboy2Base::flashlight()
{
    if (!pressed(UP_BUTTON))
    {
        return;
    }

    sendLCDCommand(OLED_ALL_PIXELS_ON); // smaller than allPixelsOn()
    digitalWriteRGB(RGB_ON, RGB_ON, RGB_ON);

#ifndef ARDUBOY_CORE // for Arduboy core timer 0 should remain enabled
    // prevent the bootloader magic number from being overwritten by timer 0
    // when a timer variable overlaps the magic number location, for when
    // flashlight mode is used for upload problem recovery
    power_timer0_disable();
#endif

    while (true)
    {
        idle();
    }
}

void Arduboy2Base::systemButtons()
{
    while (pressed(B_BUTTON))
    {
        digitalWriteRGB(BLUE_LED, RGB_ON); // turn on blue LED
        sysCtrlSound(UP_BUTTON + B_BUTTON, GREEN_LED, 0xff);
        sysCtrlSound(DOWN_BUTTON + B_BUTTON, RED_LED, 0);
        delayShort(200);
    }

    digitalWriteRGB(BLUE_LED, RGB_OFF); // turn off blue LED
}

void Arduboy2Base::sysCtrlSound(uint8_t buttons, uint8_t led, uint8_t eeVal)
{
    if (pressed(buttons))
    {
        digitalWriteRGB(BLUE_LED, RGB_OFF); // turn off blue LED
        delayShort(200);
        digitalWriteRGB(led, RGB_ON); // turn on "acknowledge" LED
        EEPROM.update(EEPROM_AUDIO_ON_OFF, eeVal);
        delayShort(500);
        digitalWriteRGB(led, RGB_OFF); // turn off "acknowledge" LED

        while (pressed(buttons)) { } // Wait for button release
    }
}

void Arduboy2Base::bootLogo()
{
    bootLogoShell(drawLogoBitmap);
}

void Arduboy2Base::drawLogoBitmap(int16_t y)
{
    drawBitmap(20, y, arduboy_logo, 88, 16);
}

void Arduboy2Base::bootLogoCompressed()
{
    bootLogoShell(drawLogoCompressed);
}

void Arduboy2Base::drawLogoCompressed(int16_t y)
{
    drawCompressed(20, y, arduboy_logo_compressed);
}

void Arduboy2Base::bootLogoSpritesSelfMasked()
{
    bootLogoShell(drawLogoSpritesSelfMasked);
}

void Arduboy2Base::drawLogoSpritesSelfMasked(int16_t y)
{
    Sprites::drawSelfMasked(20, y, arduboy_logo_sprite, 0);
}

void Arduboy2Base::bootLogoSpritesOverwrite()
{
    bootLogoShell(drawLogoSpritesOverwrite);
}

void Arduboy2Base::drawLogoSpritesOverwrite(int16_t y)
{
    Sprites::drawOverwrite(20, y, arduboy_logo_sprite, 0);
}

void Arduboy2Base::bootLogoSpritesBSelfMasked()
{
    bootLogoShell(drawLogoSpritesBSelfMasked);
}

void Arduboy2Base::drawLogoSpritesBSelfMasked(int16_t y)
{
    SpritesB::drawSelfMasked(20, y, arduboy_logo_sprite, 0);
}

void Arduboy2Base::bootLogoSpritesBOverwrite()
{
    bootLogoShell(drawLogoSpritesBOverwrite);
}

void Arduboy2Base::drawLogoSpritesBOverwrite(int16_t y)
{
    SpritesB::drawOverwrite(20, y, arduboy_logo_sprite, 0);
}

// bootLogoText() should be kept in sync with bootLogoShell()
// if changes are made to one, equivalent changes should be made to the other
void Arduboy2Base::bootLogoShell(void (*drawLogo)(int16_t))
{
    bool showLEDs = true;//readShowBootLogoLEDsFlag();

//  if (!readShowBootLogoFlag()) {
//    return;
//  }

    if (showLEDs)
    {
        digitalWriteRGB(RED_LED, RGB_ON);
    }

    for (int16_t y = -16; y <= 24; y++)
    {
        if (pressed(RIGHT_BUTTON))
        {
            digitalWriteRGB(RGB_OFF, RGB_OFF, RGB_OFF); // all LEDs off
            return;
        }

        if (showLEDs && y == 4)
        {
            digitalWriteRGB(RED_LED, RGB_OFF);    // red LED off
            digitalWriteRGB(GREEN_LED, RGB_ON);   // green LED on
        }

        // Using display(CLEAR_BUFFER) instead of clear() may save code space.
        // The extra time it takes to repaint the previous logo isn't an issue.
        display(CLEAR_BUFFER);
        (*drawLogo)(y); // call the function that actually draws the logo
        display();
        delayShort(15);
    }

    if (showLEDs)
    {
        digitalWriteRGB(GREEN_LED, RGB_OFF);  // green LED off
        digitalWriteRGB(BLUE_LED, RGB_ON);    // blue LED on
    }
    delayShort(400);
    digitalWriteRGB(BLUE_LED, RGB_OFF);

    bootLogoExtra();
}

// Virtual function overridden by derived class
void Arduboy2Base::bootLogoExtra() { }

// wait for all buttons to be released
void Arduboy2Base::waitNoButtons()
{
    do
    {
        delayShort(50); // simple button debounce
    }
    while (buttonsState());
}

/* Frame management */

void Arduboy2Base::setFrameRate(uint8_t rate)
{
    eachFrameMillis = 1000 / rate;
}

void Arduboy2Base::setFrameDuration(uint8_t duration)
{
    eachFrameMillis = duration;
}

bool Arduboy2Base::everyXFrames(uint8_t frames)
{
    return frameCount % frames == 0;
}

bool Arduboy2Base::nextFrame()
{
    uint8_t now = (uint8_t) millis();
    uint8_t frameDurationMs = now - thisFrameStart;

    if (justRendered)
    {
        lastFrameDurationMs = frameDurationMs;
        justRendered = false;
        return false;
    }
    else if (frameDurationMs < eachFrameMillis)
    {
        // Only idle if at least a full millisecond remains, since idle() may
        // sleep the processor until the next millisecond timer interrupt.
        if (++frameDurationMs < eachFrameMillis)
        {
            idle();
        }

        return false;
    }
    else if(Game_DispIsBusy())
    {
        return false;
    }

    // pre-render
    justRendered = true;
    thisFrameStart = now;
    frameCount++;

    return true;
}

bool Arduboy2Base::nextFrameDEV()
{
    bool ret = nextFrame();

    if (ret)
    {
        if (lastFrameDurationMs > eachFrameMillis)
            ;//TXLED1;
        else
            ;//TXLED0;
    }
    return ret;
}

int Arduboy2Base::cpuLoad()
{
    return lastFrameDurationMs * 100 / eachFrameMillis;
}

unsigned long Arduboy2Base::generateRandomSeed()
{
    unsigned long seed;

    return seed;
}

void Arduboy2Base::initRandomSeed()
{
    randomSeed(generateRandomSeed());
}

/* Graphics */

void Arduboy2Base::clear()
{
    fillScreen(BLACK);
}

// For reference, this is the C++ equivalent
void Arduboy2Base::drawPixel(int16_t x, int16_t y, uint8_t color)
{
#ifdef PIXEL_SAFE_MODE
    if (x < 0 || x > (WIDTH - 1) || y < 0 || y > (HEIGHT - 1))
    {
        return;
    }
#endif

    uint16_t row_offset;
    uint8_t bit;

    bit = 1 << (y & 7);
    row_offset = (y & 0xF8) * WIDTH / 8 + x;
    uint8_t data = sBuffer[row_offset] | bit;
    if (!color) data ^= bit;
    sBuffer[row_offset] = data;
}

uint8_t Arduboy2Base::getPixel(uint8_t x, uint8_t y)
{
    uint8_t row = y / 8;
    uint8_t bit_position = y % 8;
    return (sBuffer[(row * WIDTH) + x] & _BV(bit_position)) >> bit_position;
}

void Arduboy2Base::drawCircle(int16_t x0, int16_t y0, uint8_t r, uint8_t color)
{
    int16_t f = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x = 0;
    int16_t y = r;

    drawPixel(x0, y0 + r, color);
    drawPixel(x0, y0 - r, color);
    drawPixel(x0 + r, y0, color);
    drawPixel(x0 - r, y0, color);

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f += ddF_y;
        }

        x++;
        ddF_x += 2;
        f += ddF_x;

        drawPixel(x0 + x, y0 + y, color);
        drawPixel(x0 - x, y0 + y, color);
        drawPixel(x0 + x, y0 - y, color);
        drawPixel(x0 - x, y0 - y, color);
        drawPixel(x0 + y, y0 + x, color);
        drawPixel(x0 - y, y0 + x, color);
        drawPixel(x0 + y, y0 - x, color);
        drawPixel(x0 - y, y0 - x, color);
    }
}

void Arduboy2Base::drawCircleHelper
(int16_t x0, int16_t y0, uint8_t r, uint8_t corners, uint8_t color)
{
    int16_t f = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x = 0;
    int16_t y = r;

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f += ddF_y;
        }

        x++;
        ddF_x += 2;
        f += ddF_x;

        if (corners & 0x4) // lower right
        {
            drawPixel(x0 + x, y0 + y, color);
            drawPixel(x0 + y, y0 + x, color);
        }
        if (corners & 0x2) // upper right
        {
            drawPixel(x0 + x, y0 - y, color);
            drawPixel(x0 + y, y0 - x, color);
        }
        if (corners & 0x8) // lower left
        {
            drawPixel(x0 - y, y0 + x, color);
            drawPixel(x0 - x, y0 + y, color);
        }
        if (corners & 0x1) // upper left
        {
            drawPixel(x0 - y, y0 - x, color);
            drawPixel(x0 - x, y0 - y, color);
        }
    }
}

void Arduboy2Base::fillCircle(int16_t x0, int16_t y0, uint8_t r, uint8_t color)
{
    drawFastVLine(x0, y0 - r, 2 * r + 1, color);
    fillCircleHelper(x0, y0, r, 3, 0, color);
}

void Arduboy2Base::fillCircleHelper
(int16_t x0, int16_t y0, uint8_t r, uint8_t sides, int16_t delta,
 uint8_t color)
{
    int16_t f = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x = 0;
    int16_t y = r;

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f += ddF_y;
        }

        x++;
        ddF_x += 2;
        f += ddF_x;

        if (sides & 0x1) // right side
        {
            drawFastVLine(x0 + x, y0 - y, 2 * y + 1 + delta, color);
            drawFastVLine(x0 + y, y0 - x, 2 * x + 1 + delta, color);
        }

        if (sides & 0x2) // left side
        {
            drawFastVLine(x0 - x, y0 - y, 2 * y + 1 + delta, color);
            drawFastVLine(x0 - y, y0 - x, 2 * x + 1 + delta, color);
        }
    }
}

void Arduboy2Base::drawLine
(int16_t x0, int16_t y0, int16_t x1, int16_t y1, uint8_t color)
{
    // bresenham's algorithm - thx wikpedia
    bool steep = abs(y1 - y0) > abs(x1 - x0);
    if (steep)
    {
        swap(x0, y0);
        swap(x1, y1);
    }

    if (x0 > x1)
    {
        swap(x0, x1);
        swap(y0, y1);
    }

    int16_t dx, dy;
    dx = x1 - x0;
    dy = abs(y1 - y0);

    int16_t err = dx / 2;
    int8_t ystep;

    if (y0 < y1)
    {
        ystep = 1;
    }
    else
    {
        ystep = -1;
    }

    for (; x0 <= x1; x0++)
    {
        if (steep)
        {
            drawPixel(y0, x0, color);
        }
        else
        {
            drawPixel(x0, y0, color);
        }

        err -= dy;
        if (err < 0)
        {
            y0 += ystep;
            err += dx;
        }
    }
}

void Arduboy2Base::drawRect
(int16_t x, int16_t y, uint8_t w, uint8_t h, uint8_t color)
{
    drawFastHLine(x, y, w, color);
    drawFastHLine(x, y + h - 1, w, color);
    drawFastVLine(x, y, h, color);
    drawFastVLine(x + w - 1, y, h, color);
}

void Arduboy2Base::drawFastVLine
(int16_t x, int16_t y, uint8_t h, uint8_t color)
{
    int end = y + h;
    for (int a = max(0, y); a < min(end, HEIGHT); a++)
    {
        drawPixel(x, a, color);
    }
}

void Arduboy2Base::drawFastHLine
(int16_t x, int16_t y, uint8_t w, uint8_t color)
{
    int16_t xEnd; // last x point + 1

    // Do y bounds checks
    if (y < 0 || y >= HEIGHT)
        return;

    xEnd = x + w;

    // Check if the entire line is not on the display
    if (xEnd <= 0 || x >= WIDTH)
        return;

    // Don't start before the left edge
    if (x < 0)
        x = 0;

    // Don't end past the right edge
    if (xEnd > WIDTH)
        xEnd = WIDTH;

    // calculate actual width (even if unchanged)
    w = xEnd - x;

    // buffer pointer plus row offset + x offset
    register uint8_t *pBuf = sBuffer + ((y / 8) * WIDTH) + x;

    // pixel mask
    register uint8_t mask = 1 << (y & 7);

    switch (color)
    {
    case WHITE:
        while (w--)
        {
            *pBuf++ |= mask;
        }
        break;

    case BLACK:
        mask = ~mask;
        while (w--)
        {
            *pBuf++ &= mask;
        }
        break;
    }
}

void Arduboy2Base::fillRect
(int16_t x, int16_t y, uint8_t w, uint8_t h, uint8_t color)
{
    // stupidest version - update in subclasses if desired!
    for (int16_t i = x; i < x + w; i++)
    {
        drawFastVLine(i, y, h, color);
    }
}

void Arduboy2Base::fillScreen(uint8_t color)
{
    // C version:
    //
    if (color != BLACK)
    {
        color = 0xFF; // all pixels on
    }
    for (int16_t i = 0; i < WIDTH * HEIGHT / 8; i++)
    {
        sBuffer[i] = color;
    }
}

void Arduboy2Base::drawRoundRect
(int16_t x, int16_t y, uint8_t w, uint8_t h, uint8_t r, uint8_t color)
{
    // smarter version
    drawFastHLine(x + r, y, w - 2 * r, color); // Top
    drawFastHLine(x + r, y + h - 1, w - 2 * r, color); // Bottom
    drawFastVLine(x, y + r, h - 2 * r, color); // Left
    drawFastVLine(x + w - 1, y + r, h - 2 * r, color); // Right
    // draw four corners
    drawCircleHelper(x + r, y + r, r, 1, color);
    drawCircleHelper(x + w - r - 1, y + r, r, 2, color);
    drawCircleHelper(x + w - r - 1, y + h - r - 1, r, 4, color);
    drawCircleHelper(x + r, y + h - r - 1, r, 8, color);
}

void Arduboy2Base::fillRoundRect
(int16_t x, int16_t y, uint8_t w, uint8_t h, uint8_t r, uint8_t color)
{
    // smarter version
    fillRect(x + r, y, w - 2 * r, h, color);

    // draw four corners
    fillCircleHelper(x + w - r - 1, y + r, r, 1, h - 2 * r - 1, color);
    fillCircleHelper(x + r, y + r, r, 2, h - 2 * r - 1, color);
}

void Arduboy2Base::drawTriangle
(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint8_t color)
{
    drawLine(x0, y0, x1, y1, color);
    drawLine(x1, y1, x2, y2, color);
    drawLine(x2, y2, x0, y0, color);
}

void Arduboy2Base::fillTriangle
(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint8_t color)
{

    int16_t a, b, y, last;
    // Sort coordinates by Y order (y2 >= y1 >= y0)
    if (y0 > y1)
    {
        swap(y0, y1);
        swap(x0, x1);
    }
    if (y1 > y2)
    {
        swap(y2, y1);
        swap(x2, x1);
    }
    if (y0 > y1)
    {
        swap(y0, y1);
        swap(x0, x1);
    }

    if(y0 == y2)
    {
        // Handle awkward all-on-same-line case as its own thing
        a = b = x0;
        if(x1 < a)
        {
            a = x1;
        }
        else if(x1 > b)
        {
            b = x1;
        }
        if(x2 < a)
        {
            a = x2;
        }
        else if(x2 > b)
        {
            b = x2;
        }
        drawFastHLine(a, y0, b - a + 1, color);
        return;
    }

    int16_t dx01 = x1 - x0,
            dy01 = y1 - y0,
            dx02 = x2 - x0,
            dy02 = y2 - y0,
            dx12 = x2 - x1,
            dy12 = y2 - y1,
            sa = 0,
            sb = 0;

    // For upper part of triangle, find scanline crossings for segments
    // 0-1 and 0-2.  If y1=y2 (flat-bottomed triangle), the scanline y1
    // is included here (and second loop will be skipped, avoiding a /0
    // error there), otherwise scanline y1 is skipped here and handled
    // in the second loop...which also avoids a /0 error here if y0=y1
    // (flat-topped triangle).
    if (y1 == y2)
    {
        last = y1;   // Include y1 scanline
    }
    else
    {
        last = y1 - 1; // Skip it
    }


    for(y = y0; y <= last; y++)
    {
        a   = x0 + sa / dy01;
        b   = x0 + sb / dy02;
        sa += dx01;
        sb += dx02;

        if(a > b)
        {
            swap(a, b);
        }

        drawFastHLine(a, y, b - a + 1, color);
    }

    // For lower part of triangle, find scanline crossings for segments
    // 0-2 and 1-2.  This loop is skipped if y1=y2.
    sa = dx12 * (y - y1);
    sb = dx02 * (y - y0);

    for(; y <= y2; y++)
    {
        a   = x1 + sa / dy12;
        b   = x0 + sb / dy02;
        sa += dx12;
        sb += dx02;

        if(a > b)
        {
            swap(a, b);
        }

        drawFastHLine(a, y, b - a + 1, color);
    }
}

void Arduboy2Base::drawBitmap
(int16_t x, int16_t y, const uint8_t *bitmap, uint8_t w, uint8_t h,
 uint8_t color)
{
    // no need to draw at all if we're offscreen
    if (x + w < 0 || x > WIDTH - 1 || y + h < 0 || y > HEIGHT - 1)
        return;

    int yOffset = abs(y) % 8;
    int sRow = y / 8;
    if (y < 0)
    {
        sRow--;
        yOffset = 8 - yOffset;
    }
    int rows = h / 8;
    if (h % 8 != 0) rows++;
    for (int a = 0; a < rows; a++)
    {
        int bRow = sRow + a;
        if (bRow > (HEIGHT / 8) - 1) break;
        if (bRow > -2)
        {
            for (int iCol = 0; iCol < w; iCol++)
            {
                if (iCol + x > (WIDTH - 1)) break;
                if (iCol + x >= 0)
                {
                    if (bRow >= 0)
                    {
                        if (color == WHITE)
                            sBuffer[(bRow * WIDTH) + x + iCol] |= pgm_read_byte(bitmap + (a * w) + iCol) << yOffset;
                        else if (color == BLACK)
                            sBuffer[(bRow * WIDTH) + x + iCol] &= ~(pgm_read_byte(bitmap + (a * w) + iCol) << yOffset);
                        else
                            sBuffer[(bRow * WIDTH) + x + iCol] ^= pgm_read_byte(bitmap + (a * w) + iCol) << yOffset;
                    }
                    if (yOffset && bRow < (HEIGHT / 8) - 1 && bRow > -2)
                    {
                        if (color == WHITE)
                            sBuffer[((bRow + 1)*WIDTH) + x + iCol] |= pgm_read_byte(bitmap + (a * w) + iCol) >> (8 - yOffset);
                        else if (color == BLACK)
                            sBuffer[((bRow + 1)*WIDTH) + x + iCol] &= ~(pgm_read_byte(bitmap + (a * w) + iCol) >> (8 - yOffset));
                        else
                            sBuffer[((bRow + 1)*WIDTH) + x + iCol] ^= pgm_read_byte(bitmap + (a * w) + iCol) >> (8 - yOffset);
                    }
                }
            }
        }
    }
}


void Arduboy2Base::drawSlowXYBitmap
(int16_t x, int16_t y, const uint8_t *bitmap, uint8_t w, uint8_t h, uint8_t color)
{
    // no need to draw at all of we're offscreen
    if (x + w < 0 || x > WIDTH - 1 || y + h < 0 || y > HEIGHT - 1)
        return;

    int16_t xi, yi, byteWidth = (w + 7) / 8;
    for(yi = 0; yi < h; yi++)
    {
        for(xi = 0; xi < w; xi++ )
        {
            if(pgm_read_byte(bitmap + yi * byteWidth + xi / 8) & (128 >> (xi & 7)))
            {
                drawPixel(x + xi, y + yi, color);
            }
        }
    }
}


// Helper for drawCompressed()
struct BitStreamReader
{
    const uint8_t *source;
    uint16_t sourceIndex;
    uint8_t bitBuffer;
    uint8_t byteBuffer;

    BitStreamReader(const uint8_t *source)
        : source(source), sourceIndex(), bitBuffer(), byteBuffer()
    {
    }

    uint16_t readBits(uint16_t bitCount)
    {
        uint16_t result = 0;
        for (uint16_t i = 0; i < bitCount; i++)
        {
            if (this->bitBuffer == 0)
            {
                this->bitBuffer = 0x1;
                this->byteBuffer = pgm_read_byte(&this->source[this->sourceIndex]);
                ++this->sourceIndex;
            }

            if ((this->byteBuffer & this->bitBuffer) != 0)
                result |= (1 << i);

            this->bitBuffer <<= 1;
        }
        return result;
    }
};

void Arduboy2Base::drawCompressed(int16_t sx, int16_t sy, const uint8_t *bitmap, uint8_t color)
{
    // set up decompress state
    BitStreamReader cs = BitStreamReader(bitmap);

    // read header
    int width = (int)cs.readBits(8) + 1;
    int height = (int)cs.readBits(8) + 1;
    uint8_t spanColour = (uint8_t)cs.readBits(1); // starting colour

    // no need to draw at all if we're offscreen
    if ((sx + width < 0) || (sx > WIDTH - 1) || (sy + height < 0) || (sy > HEIGHT - 1))
        return;

    // sy = sy - (frame * height);
    int yOffset = abs(sy) % 8;
    int startRow = sy / 8;
    if (sy < 0)
    {
        startRow--;
        yOffset = 8 - yOffset;
    }
    int rows = height / 8;
    if ((height % 8) != 0)
        ++rows;

    int rowOffset = 0; // +(frame*rows);
    int columnOffset = 0;

    uint8_t byte = 0x00;
    uint8_t bit = 0x01;
    while (rowOffset < rows) // + (frame*rows))
    {
        uint16_t bitLength = 1;
        while (cs.readBits(1) == 0)
            bitLength += 2;

        uint16_t len = cs.readBits(bitLength) + 1; // span length

        // draw the span
        for (uint16_t i = 0; i < len; ++i)
        {
            if (spanColour != 0)
                byte |= bit;
            bit <<= 1;

            if (bit == 0) // reached end of byte
            {
                // draw
                int bRow = startRow + rowOffset;

                //if (byte) // possible optimisation
                if ((bRow <= (HEIGHT / 8) - 1) && (bRow > -2) &&
                        (columnOffset + sx <= (WIDTH - 1)) && (columnOffset + sx >= 0))
                {
                    int16_t offset = (bRow * WIDTH) + sx + columnOffset;
                    if (bRow >= 0)
                    {
                        int16_t index = offset;
                        uint8_t value = byte << yOffset;

                        if (color != 0)
                            sBuffer[index] |= value;
                        else
                            sBuffer[index] &= ~value;
                    }
                    if ((yOffset != 0) && (bRow < (HEIGHT / 8) - 1))
                    {
                        int16_t index = offset + WIDTH;
                        uint8_t value = byte >> (8 - yOffset);

                        if (color != 0)
                            sBuffer[index] |= value;
                        else
                            sBuffer[index] &= ~value;
                    }
                }

                // iterate
                ++columnOffset;
                if (columnOffset >= width)
                {
                    columnOffset = 0;
                    ++rowOffset;
                }

                // reset byte
                byte = 0x00;
                bit = 0x01;
            }
        }

        spanColour ^= 0x01; // toggle colour bit (bit 0) for next span
    }
}

void Arduboy2Base::display()
{
    paintScreen(sBuffer);
}

void Arduboy2Base::display(bool clear)
{
    paintScreen(sBuffer, clear);
}

uint8_t* Arduboy2Base::getBuffer()
{
    return sBuffer;
}

bool Arduboy2Base::pressed(uint8_t buttons)
{
    return (buttonsState() & buttons) == buttons;
}

bool Arduboy2Base::notPressed(uint8_t buttons)
{
    return (buttonsState() & buttons) == 0;
}

void Arduboy2Base::pollButtons()
{
    previousButtonState = currentButtonState;
    currentButtonState = buttonsState();
}

bool Arduboy2Base::justPressed(uint8_t button)
{
    return (!(previousButtonState & button) && (currentButtonState & button));
}

bool Arduboy2Base::justReleased(uint8_t button)
{
    return ((previousButtonState & button) && !(currentButtonState & button));
}

bool Arduboy2Base::collide(Point point, Rect rect)
{
    return ((point.x >= rect.x) && (point.x < rect.x + rect.width) &&
            (point.y >= rect.y) && (point.y < rect.y + rect.height));
}

bool Arduboy2Base::collide(Rect rect1, Rect rect2)
{
    return !(rect2.x                >= rect1.x + rect1.width  ||
             rect2.x + rect2.width  <= rect1.x                ||
             rect2.y                >= rect1.y + rect1.height ||
             rect2.y + rect2.height <= rect1.y);
}

uint16_t Arduboy2Base::readUnitID()
{
    return EEPROM.read(EEPROM_UNIT_ID) |
           (((uint16_t)(EEPROM.read(EEPROM_UNIT_ID + 1))) << 8);
}

void Arduboy2Base::writeUnitID(uint16_t id)
{
    EEPROM.update(EEPROM_UNIT_ID, (uint8_t)(id & 0xff));
    EEPROM.update(EEPROM_UNIT_ID + 1, (uint8_t)(id >> 8));
}

uint8_t Arduboy2Base::readUnitName(char* name)
{
    char val;
    uint8_t dest;
    uint8_t src = EEPROM_UNIT_NAME;

    for (dest = 0; dest < ARDUBOY_UNIT_NAME_LEN; dest++)
    {
        val = EEPROM.read(src);
        name[dest] = val;
        src++;
        if (val == 0x00 || (byte)val == 0xFF)
        {
            break;
        }
    }

    name[dest] = 0x00;
    return dest;
}

void Arduboy2Base::writeUnitName(char* name)
{
    bool done = false;
    uint8_t dest = EEPROM_UNIT_NAME;

    for (uint8_t src = 0; src < ARDUBOY_UNIT_NAME_LEN; src++)
    {
        if (name[src] == 0x00)
        {
            done = true;
        }
        // write character or 0 pad if finished
        EEPROM.update(dest, done ? 0x00 : name[src]);
        dest++;
    }
}

bool Arduboy2Base::readShowBootLogoFlag()
{
    return (EEPROM.read(EEPROM_SYS_FLAGS) & SYS_FLAG_SHOW_LOGO_MASK);
}

void Arduboy2Base::writeShowBootLogoFlag(bool val)
{
    uint8_t flags = EEPROM.read(EEPROM_SYS_FLAGS);

    bitWrite(flags, SYS_FLAG_SHOW_LOGO, val);
    EEPROM.update(EEPROM_SYS_FLAGS, flags);
}

bool Arduboy2Base::readShowUnitNameFlag()
{
    return (EEPROM.read(EEPROM_SYS_FLAGS) & SYS_FLAG_UNAME_MASK);
}

void Arduboy2Base::writeShowUnitNameFlag(bool val)
{
    uint8_t flags = EEPROM.read(EEPROM_SYS_FLAGS);

    bitWrite(flags, SYS_FLAG_UNAME, val);
    EEPROM.update(EEPROM_SYS_FLAGS, flags);
}

bool Arduboy2Base::readShowBootLogoLEDsFlag()
{
    return (EEPROM.read(EEPROM_SYS_FLAGS) & SYS_FLAG_SHOW_LOGO_LEDS_MASK);
}

void Arduboy2Base::writeShowBootLogoLEDsFlag(bool val)
{
    uint8_t flags = EEPROM.read(EEPROM_SYS_FLAGS);

    bitWrite(flags, SYS_FLAG_SHOW_LOGO_LEDS, val);
    EEPROM.update(EEPROM_SYS_FLAGS, flags);
}

void Arduboy2Base::swap(int16_t& a, int16_t& b)
{
    int16_t temp = a;
    a = b;
    b = temp;
}


//====================================
//========== class Arduboy2 ==========
//====================================

Arduboy2::Arduboy2()
{
    cursor_x = 0;
    cursor_y = 0;
    textColor = 1;
    textBackground = 0;
    textSize = 1;
    textWrap = 0;
}

// bootLogoText() should be kept in sync with bootLogoShell()
// if changes are made to one, equivalent changes should be made to the other
void Arduboy2::bootLogoText()
{
    bool showLEDs = readShowBootLogoLEDsFlag();

    if (!readShowBootLogoFlag())
    {
        return;
    }

    if (showLEDs)
    {
        digitalWriteRGB(RED_LED, RGB_ON);
    }

    for (int16_t y = -16; y <= 24; y++)
    {
        if (pressed(RIGHT_BUTTON))
        {
            digitalWriteRGB(RGB_OFF, RGB_OFF, RGB_OFF); // all LEDs off
            return;
        }

        if (showLEDs && y == 4)
        {
            digitalWriteRGB(RED_LED, RGB_OFF);    // red LED off
            digitalWriteRGB(GREEN_LED, RGB_ON);   // green LED on
        }

        // Using display(CLEAR_BUFFER) instead of clear() may save code space.
        // The extra time it takes to repaint the previous logo isn't an issue.
        display(CLEAR_BUFFER);
        cursor_x = 23;
        cursor_y = y;
        textSize = 2;
        print(F("ARDUBOY"));
        textSize = 1;
        display();
        delayShort(11);
    }

    if (showLEDs)
    {
        digitalWriteRGB(GREEN_LED, RGB_OFF);  // green LED off
        digitalWriteRGB(BLUE_LED, RGB_ON);    // blue LED on
    }
    delayShort(400);
    digitalWriteRGB(BLUE_LED, RGB_OFF);

    bootLogoExtra();
}

void Arduboy2::bootLogoExtra()
{
    uint8_t c;

    if (!readShowUnitNameFlag())
    {
        return;
    }

    c = EEPROM.read(EEPROM_UNIT_NAME);

    if (c != 0xFF && c != 0x00)
    {
        uint8_t i = EEPROM_UNIT_NAME;
        cursor_x = 50;
        cursor_y = 56;

        do
        {
            write(c);
            c = EEPROM.read(++i);
        }
        while (i < EEPROM_UNIT_NAME + ARDUBOY_UNIT_NAME_LEN);

        display();
        delayShort(1000);
    }
}

size_t Arduboy2::write(uint8_t c)
{
    if (c == '\n')
    {
        cursor_y += textSize * 8;
        cursor_x = 0;
    }
    else if (c == '\r')
    {
        // skip em
    }
    else
    {
        drawChar(cursor_x, cursor_y, c, textColor, textBackground, textSize);
        cursor_x += textSize * 6;
        if (textWrap && (cursor_x > (WIDTH - textSize * 6)))
        {
            // calling ourselves recursively for 'newline' is
            // 12 bytes smaller than doing the same math here
            write('\n');
        }
    }
    return 1;
}

void Arduboy2::drawChar
(int16_t x, int16_t y, unsigned char c, uint8_t color, uint8_t bg, uint8_t size)
{
    uint8_t line;
    bool draw_background = bg != color;
    const unsigned char* bitmap = font + c * 5;

    if ((x >= WIDTH) ||              // Clip right
            (y >= HEIGHT) ||             // Clip bottom
            ((x + 5 * size - 1) < 0) ||  // Clip left
            ((y + 8 * size - 1) < 0)     // Clip top
       )
    {
        return;
    }

    for (uint8_t i = 0; i < 6; i++ )
    {
        line = pgm_read_byte(bitmap++);
        if (i == 5)
        {
            line = 0x0;
        }

        for (uint8_t j = 0; j < 8; j++)
        {
            uint8_t draw_color = (line & 0x1) ? color : bg;

            if (draw_color || draw_background)
            {
                for (uint8_t a = 0; a < size; a++ )
                {
                    for (uint8_t b = 0; b < size; b++ )
                    {
                        drawPixel(x + (i * size) + a, y + (j * size) + b, draw_color);
                    }
                }
            }
            line >>= 1;
        }
    }
}

void Arduboy2::setCursor(int16_t x, int16_t y)
{
    cursor_x = x;
    cursor_y = y;
}

int16_t Arduboy2::getCursorX()
{
    return cursor_x;
}

int16_t Arduboy2::getCursorY()
{
    return cursor_y;
}

void Arduboy2::setTextColor(uint8_t color)
{
    textColor = color;
}

uint8_t Arduboy2::getTextColor()
{
    return textColor;
}

void Arduboy2::setTextBackground(uint8_t bg)
{
    textBackground = bg;
}

uint8_t Arduboy2::getTextBackground()
{
    return textBackground;
}

void Arduboy2::setTextSize(uint8_t s)
{
    // size must always be 1 or higher
    textSize = max(1, s);
}

uint8_t Arduboy2::getTextSize()
{
    return textSize;
}

void Arduboy2::setTextWrap(bool w)
{
    textWrap = w;
}

bool Arduboy2::getTextWrap()
{
    return textWrap;
}

void Arduboy2::clear()
{
    Arduboy2Base::clear();
    cursor_x = cursor_y = 0;
}

